The location of the pine is of great importance.
Here in Northern Wisconsin, 14 year old pine is just "getting started" towards its maturity of 70 years or so. Very little timber value, but great potential for the future, which will see exorbitant demand for timber.
In southern climates, where trees grow much faster, its possible you may have something ready for its "first thinning". Don't plan on "getting fat" from the proceeds of the first thinning.....there won't be much.
And if property taxes are high, consider placing the property in a "Managed Forest" type program. Wisconsin has a program such as this.... as do most other states. Property taxes are as low as $1/acre when enrolled in this program. When and if, any timber is harvested from the plot while enrolled in this program, a person is required to pay 5% of the value of the stumpage to the state to administer the program. This is a real bargain!
An honest forester or an honest logger (both are hard to find) can tell you what the pine plantation is worth, as well as your best course of action.